Luminous signs



Aug- 1957 G. P. COOPER ETAL 2,801,483

LUMINOUS SIGNS 2 Sheets-Sheet 1 Filed Dec. 29, 1954 A w l m s w 0 R H mET T GE R T Omw/ H Aug. 6, 1957 4 G. P. COOPER ETAL LUMINOUS SIGNS 2Sheets-Sheet 2 Filed Dec. 29, 1954 mm N? IN V EN TOR. GEORGE I? COOPERKENNETH 0. KELLY ATTORNE Y5 United States Patent LUMINOUS' SIGNS GeorgeP. Cooper, Barberton, and Kenneth 0. Kelly, Akron, Ohio, assignors toMercu-Ray industries, Inc, Columbus, Ohio, a corporation of OhioApplication December 29, 1954, Serial No. 47 8,388

1. Claim. (Cl. ilk-130) This invention relates to changeable signs, andin particular to the type of changeable sign in which glass tubescontaining vapor or gas form the letters of the sign, and which lettershave no electrical connection with the sign but are, rather, detachabletherefrom and shiftable therein so that the sign can be changed at anytime and can be arranged in any desired way.

An object of this invention is the provision of. a sign of the naturereferred to in which the letters or characters supported in the sign areeasily removed therefrom or placed therein, but without'there being anydanger that the letters will get out of place in the sign or falltherefrom.

Another object of this invention is the provision of an arrangement inconnection with the sign for creating an electrical field forilluminating the letters placed in the sign, but which electrical fieldis contained within a relatively small region whereby the influence ofthe electrical field is practically confined to the letters carried bythe sign.

A further object of this invention is the provision of an energizingcircuit for a sign of the nature referred to in which the circuit isquite simple and employs the fewest number of tubes and other fragilecomponents.

A still further object of this invention is the provision of a sign ofthe nature referred to which is simple in construction and which canreadily be dismantled for adjustment or repair if necessary.

These and other objects and advantages of this invention will becomemore apparent upon reference to the following specification taken inconnection with the accompanying drawings, in which:

Figure 1 is a perspective view partly broken away showing. a signconstructed according to this invention;

Figure 2 is a transverse sectional view indicated by the cutting planeofline 2-2 on Figure 1;

Figure 3 is afragmentary sectional view indicated by line 33 on Figure 2showing. the arrangement in the unit of the high frequency high voltageelectrode, by means of which the characters are energized to the pointof luminescence; and

Figure 4 is a more or less diagrammatic representation of the energizingcircuit of the device.

Referring to the drawings somewhat inmore detail, the unit, as it isdisclosed in Figures 1 through 3, comprises a main housing portion whichconsists of a generally channel-shaped member, preferably of sheetmetal, which has the forward edges of its top and bottom walls bentinwardly as at 12.

The inwardly turned portions 12 fit into grooves formed in alongitudinally extending top member 14 and .a longitudinally extendingbottom member 16. Screws 18 retain the top member 14 in place Whilescrews 20 retain the bottom member 16 in place, and at the same timeserve to hold the supporting feet 22 in position. Corresponding feet 24are supported toward the rear of the bottom wall of the housing.

Patented Aug. 6, 1957 ice Top member 14 is grooved on its underneathside toward the rear, and bottom member 16 is similarly grooved on itsupper side toward the rear, and these grooves serve to retain asupporting panel 26 in position.

This supporting panel is of wood or plastic, or of some othernon-conductive material, which will not interfere with the electricalfield that is to be established by the device.

In about the center of panel 26, and extending. longitudinallytherealong, there is supported a center rail 28. Center rail 28' isformed with a relatively deep trough along its upper side correspondingwith the similarly formed deep trough in the upper side of lower member16.

The underneath side of center member 28 is formed with a slight downwardincline, and this corresponds to a slight downward incline that isformed on the underneath side of upper member 14.

As will be seen in Figure 2, the troughs formed in the top of lowermember 16 and center member 28 cooperate with the inclines formed on theunderneath side of the members thereabovefor retaining the tubular glasscharacters 30 in position in the sign so that they can readily beinserted therein or readily detached therefrom.

For holding the tubular characters in position, the bot tom. of each ofthe center troughs may advantageously include a length of rubber tubingor other continuous resilient element, as at 32; the provision of thiselement serving to hold the tubes upwardly against the inclined surfacesat their upper ends.

Each end of the housing is formed with turned-in flange means as at 34,and these flange means are availed of for receiving. screws 36 whichretain the end closure panels 38 in position on the ends of the housing.These closure members are preferably of non-conductive material, such aswood or plastic.

Located within the housing, and supported at itsforward edge on thebottom edge of the housing and its rear edge on the back Wall of thehousing, is platform 40 serving as a chassis to support the principalcomponents of the electronic circuit, byvmeans of which the tubularcharacters referred to are energized. The principal components of theelectronic circuit are generally located within the device in Figures 1and 2 and illustrated in diagrammatic form in the electric circuit ofFigure 4.

Referring to Figure 4, together with Figure l, the energizing circuitwill. be seen to comprise a cable 50 having a plug 52 on the end, bymeans-of which the unit can be plugged into an electric outlet ofnominal volt rating.

The cable leads to the housing of the device and, at the housing end,the cable has. in circuit therewith an on-ofi switch 54 and a fuse 56.Connected across the cable within. the housing is a-transformer 58 whichsupplies the heaters 60' of the oscillator tubes of the circuit. Thecable preferably includes a third wire 55 having one end connected tothe chassis ground, and the other end provided with a connector clip 57.

One side of the line established by the cable in the housing leadsthrough to an electrolytic condenser 62 and a selenium rectifier 64 to afilter network comprising radio frequency choke 66 and capacitors 68 and70 connected between opposite ends of radio frequency choke 66 and theopposite side of the line.

Capacitor 68 is preferably an electrolytic condenser, and capacitor 70may advantageously be a paper condenser considerably smaller thancapacitor 68. Capacitor 62 is likewise an electrolytic condenser ofabout the same rating as the capacitor 68.

Resistor 63 is preferably provided to protect the capacitors and'rectifiers from large current surges during the A. C. line peaks.

A second selenium rectifier 72 is connected between capacitor 62 andrectifier 64 in the opposite side of the line. This arrangementrepresents a voltage doubling circuit so that power is drawn from theelectric circuit on both half. cycles, with all of the power beingvdelivered to the filter circuit on the half cycle during which the sideof the line leading to capacitor 62 is positive. This eliminates thenecessity for the conventional full wave rectifier, thus reducing thecost of the circuit and replacing the more or less fragile rectifiertubes with the sturdier rectifiers referred to.

According to this invention two oscillator tubes connected in parallelare employed, but it will be evident that, since these tubes are inparallel, one tube of larger capacity could be employed and satisfactoryresults would be obtained. However, it is preferred to employ two tubesin parallel since either one of the tubes will maintain the tubesilluminated so that failure of one tube will not cause the sign tobecome inoperative.

The two tubes, which may be 6L6s, are located at 72 and 74. These arethe tubes supplied by the heaters 60 previously referred to. Thecathodes 76 of the tubes are connected with ground via condenser 78,said ground consisting of a connection with the chassis platform 40. Thecathodes are also connected with the side of the line opposite the sideconnected with capacitor 62.

Each tube has internally connected beam-forming electrodes (not shown),a control grid 82, and a screen grid 84. The screen grids of the tubeare connected together and then through a capacitor 86 with the cathodesof the tubes.

The screen grids are also connected through a resistor 88 of substantialsize, with the right end of the filter network, as it is viewed inFigure 4, and also with one end of a tank circuit comprising the primarycoil 90 of a radio frequency transformer indicated generally at 92, andwith the capacitors 94 and 96 being connected in parallel with coil 90.

At least capacitor 96 is adjustable so that the circuit can be tuned.The other end of the tank circuit is connected through the resistors 98with the plates 100 of the tubes 72 and 74.

The radio frequency transformer 92 also comprises a coil 102, one end ofwhich is connected through the resistors 104 with the control grids 82of the tubes 72 and 74, and the other end of which is connected throughthe resistor 106 with the cathodes of the tubes, with a capacitor 108being provided for by-passing resistor 106. The radio frequencytransformer 92 also comprises a series of seven serially connectedsecondary coils 110, with one end of the serially connected group ofcoils being connected to ground, and the other end leading via wire 112to a loop of wire 114 which is associated with center member 28 that ismounted on the front panel 26 of the device.

Loop 114 is preferably in the form of a figure 8, as will be seenparticularly in Figure 3, and may be fastened to member 28 or actuallycontained therein if desired. This element is shown as wire, but it willbe understood that a flat ribbon could be employed if so desired.

The element is also referred to as being located in member 28, but itwill be apparent that it could also be located in panel 26 if sodesired; the essential thing being that the element 28 is located inrelatively close proximity with the tubes in each of the two tiers ofthe display device where characters are mounted.

Because of the arrangement of the present invention,

. wherein the element 114 is located in about the center of the frontpanel, the electric field established thereby is limited to that regionin the front of the display device in which the tubes are to be locatedand slightly outwardly therefrom. We refer to this as a contained field.Thus, signs according to the present invention can be placed in closeproximity with each other without interfering with one another and,similarly, the sign does not produce any objectionable radiointerference.

No particular reference has been made as to the exact nature of thesealed glass tubes forming the characters of the sign since theseelements per se are well known in the art.

What these tubes consist of are glass tubes, either with or without aninternal fiuoresent or frosted coating, and containing gas such as neon,argon or helium, and with or without mercury vapor; the exact nature ofthe contents of the tubes being determined by the color desired.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions, and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claim.

We claim:

In an illuminated sign, a frame comprising a horizontally extendingtrough of sheet metal open at the front, a front panel of insulatingmaterial closing the front of the frame, means extending transverselyalong the bottom edges of said panel and along the center thereofforming upwardly opening grooves to receive tubular characters thatluminesce in an electric field, an oscillator in said frame having ahigh frequency terminal, and a single loop electrode including a lineand return in the center of said panel substantially midway between thetop of the characters in said means extending along said bottom edge andthe bottom of the characters in said means extending along the center ofsaid panel to establish a single contained field extendinglongitudinally of said panel to energize all of characters.

References Cited in the file of this patent UNITED STATES PATENTS2,291,467 Goldberg July 28, 1942 2,305,942 Weiss Dec. 22, 1942 2,322,008Fodor June 15, 1943 2,362,157 Quill Nov. 7, 1944 2,519,302 Weincord Aug.15, 1950 FOREIGN PATENTS 507,906 Great Britain June 19, 1939 1,022,908France Dec. 24, 1952

